The GOP Senate candidate, who won the U.S. Chamber endorsement at the end of June, has constantly criticized her opponent Ken Buck[3] for more than $1.5 million in ads he’s enjoyed from outside group called the Americans for Job Security since last winter.

She often calls the group “shady” and says the outside money is coming from Hensel Phelps Construction CEO and Buck friend Jerry Morgensen, but because the group doesn’t have to disclose donor lists it’s unclear who is paying for the commercials and mailers. It is illegal for any campaign to coordinate with outside groups for advertising or any kind of help.

But the U.S. Chamber is the same kind of group. Classified as a 501c(6), the organization doesn’t have to disclose its donors. The commercials, running statewide, are pro-Norton.

Norton spokeswoman Cinamon Watson said they are happy to have the U.S. Chamber endorsement.

“Looks like someone didn’t want one man to buy a US Senate seat!” said Norton campaign manager Josh Penry, in reference to Morgensen.